In our study, the downregulated genes associated with TAO were identified as PLP2, CCL4, CCL4L1, CCL4L2, EGR1, RPL9, LAMP2, PRKACA, TOP2B, DGKZ, ANPEP, TCIRG1, NDUFA1, HBB, and RPL32. Here, HBB is linked to thromboangiitis obliterans.